watwuf already said it nice, that is anything but real life. Not counted in is that there is also very serious selection criteria (so, not random people). On t

watwuf already said it nice, that is anything but real life. Not counted in is that there is also very serious selection criteria (so, not random people). On the other hand what you call extreme situation is nothing like that - most people have some type of chronic problem. The most improtant aspect is certainly longevity of treatment - callorie restriction can not be followed - it can for some time, but soon enough (months or years) you will sucumb. Its simply not a normal way to have a life. It must be sustainable life practice, not something you apply from time to time.